Massively multiplayer online (“MMO”) games enjoy tremendous popularity, with some games numbering players in the hundreds of thousands or even millions. Such games' players typically control one or more player characters; as a player plays the game, their player character generally increases in ability and power. These character attributes are often encapsulated in the form of a character level, which is a number that increases with character experience, and which is a general indicator of the ability of the character in combat, defense, or the like.
In these prior systems, progressing a player character, e.g., raising its level or increasing its combat ability, was accomplished by the process of playing the character, e.g., completing quests, performing combat, and so on. In one prior system, extra “experience points” have been given to a character following a period of non-use (so that a player could “catch up” to their friends); but these extra points are tied to new experience points gained by the character, i.e., they did not accumulate over time during the period of non-use.